(JTA) — Twitter has removed a handful of racist tweets and suspended several accounts after a German-Israeli satirist stenciled about 30 of them outside the company’s offices in Hamburg.

Shahak Shapira used spray-paint to write the nearly 30 offensive tweets on Twitter’s building and on the pavement around it. He claimed responsibility for the act on Monday in a tweet, which said: “I reported about 300 hate tweets. Twitter didn’t delete ’em, so I sprayed them in front of their office.”

The tweets included “Let’s get together and gas Jews again … the old days were nice.” And “Here comes another horde of migrants. Did they miss the stop at Auschwitz?”

By Wednesday, Twitter had deleted three tweets, suspended four accounts and withheld seven accounts in Germany, the Associated Press reported. Fifteen other posts, with racist and anti-Semitic content, remain on Twitter, according to the AP.

Twitter has not responded directly to Shapira, he said.

“It would be nice if Twitter had reacted,” Shapira told the AP. “What I want is that these flagged posts are reviewed the way Facebook does. What Facebook does isn’t perfect, but at least they are making an effort.”

A video Shapira posted of him spray-painting the offending tweets received over 100,000 views in 48 hours.

In the video, Shapira says he reported some 450 violent hate comments to Twitter and Facebook. Facebook removed about 80 percent of the comments he reported. But Twitter answered only nine of his 300 complaints, in each case noting that the tweets did not violate company policy.

Shapira gained notoriety worldwide in January when he created his Yolocaust website, which was meant to shame people who posted photos of themselves posing at Berlin’s Holocaust memorial. He removed the postings upon request of the outed and apologetic subjects.